Veterinary World最新文献

Background and aim: Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) are increasingly recognized as important pathogens in companion animals, with significant zoonotic and public health implications. Data on methicillin-resistant staphylococci in pets in Indonesia remain scarce, particularly from clinical settings. This study aimed to determine the occurrence, molecular identity, and antimicrobial resistance (AMR) profiles of MRSA and MRSP isolated from companion animals presenting with clinical infections using an integrated phenotypic and genotypic diagnostic approach.

Materials and methods: We collected 100 clinical swab samples from dogs (n = 26), cats (n = 67), and rabbits (n = 7) presenting with signs of bacterial infection at veterinary clinics in Central Java and the Special Region of Yogyakarta, Indonesia. Isolates were identified using standard biochemical tests and confirmed molecularly by PCR targeting the 23S rRNA and nuc genes for S. aureus and PCR-restriction fragment length polymorphismof the pta gene for S. pseudintermedius. Methicillin resistance was screened using oxacillin resistance screening agar base, phenotypically confirmed by disk diffusion (cefoxitin or oxacillin), and genotypically verified by detection of the mecA gene. The Kirby-Bauer method was used to perform antimicrobial susceptibility testing against 11 commonly used antibiotics.

Results: Of the 100 samples, 41 S. aureus and 14 S. pseudintermedius isolates were confirmed. Based on mecA detection, 27/41 (65.9%) S. aureus isolates were classified as MRSA and 13/14 (92.9%) S. pseudintermedius isolates were classified as MRSP. MDR was highly prevalent, observed in 92.6% of MRSA and 92.3% of MRSP isolates. High resistance rates were noted against β-lactam antibiotics, including penicillin, ampicillin, and amoxicillin. Several isolates carried mecA despite being phenotypically susceptible, indicating silent or low-expression resistance determinants.

Conclusion: This study reveals a great burden of methicillin- and multidrug-resistant staphylococci among companion animals with clinical infections in Indonesia. The detection of mecA-positive MRSA and MRSP underscores a substantial zoonotic risk and highlights the limitations of phenotypic methods. These findings emphasize the need for routine molecular diagnostics, strengthened antimicrobial stewardship in veterinary practice, and integrated One Health surveillance to mitigate the spread of AMR across animal-human interfaces.

Background and aim: Transforming growth factor-β2 (TGF-β2) and vascular endothelial growth factor (VEGF) are key mediators of inflammation, fibrosis, and angiogenesis in ocular surface disease. However, their roles in canine keratoconjunctivitis sicca (KCS) are not well understood. This study aimed to compare conjunctival TGF-β2 and VEGF levels between healthy dogs and those with KCS, evaluate the effects of 6-week therapy with 0.2% cyclosporine A (CsA), and explore associations with clinical signs, Schirmer tear test-1 (STT-1), goblet cell density (GCD), and inflammatory cell infiltration.

Materials and methods: Thirty-three dogs with KCS, classified as mild (n = 10), moderate (n = 10), or severe (n = 13), underwent ophthalmic exams, STT-1 measurements, and conjunctival biopsies before treatment (T0) and after 6 weeks of topical CsA therapy (T1). Fourteen healthy dogs served as controls. Conjunctival samples were analyzed for GCD, inflammatory cell counts, and TGF-β2 and VEGF levels using histology and enzyme-Linked Immunosorbent Assay. Clinical scoring and corneal vascular quantification were performed using standardized protocols. Statistical comparisons were made within and between groups, as well as through correlation analyses.

Results: CsA significantly increased STT-1 in all KCS grades and improved selected clinical signs. GCD in KCS dogs increased at T1, reaching levels comparable to controls, although not statistically significant. Neutrophils were the only inflammatory cells to significantly decrease after treatment. Overall, TGF-β2 levels did not differ between controls and KCS dogs; however, concentrations increased with disease severity and showed a positive correlation with lymphocyte counts and corneal melanosis, and a negative correlation with GCD. VEGF levels were mildly elevated in KCS but decreased significantly following CsA treatment, especially in severe cases, and correlated positively with corneal melanosis and negatively with corneal vessel counts. A positive correlation was observed between TGF-β2 and VEGF.

Conclusion: Topical 0.2% CsA improves tear production, GCD restoration, and various clinical signs in canine KCS. TGF-β2 seems to have a pro-inflammatory and profibrotic role, increasing with disease severity and linked to chronic ocular surface changes. CsA effectively decreases VEGF, especially in severe KCS, indicating partial modulation of angiogenic pathways. Longer treatment durations may be necessary to influence TGF-β2-mediated tissue remodeling.

Background and aim: Antimicrobial resistance (AMR) has emerged as a major One Health threat driven by inappropriate antimicrobial use (AMU) in humans, animals, and the environment. Poultry production is recognized as a key reservoir of antimicrobial-resistant bacteria, yet few studies in Kenya examine AMU and AMR across interconnected human-animal-environment domains. This study assessed AMU patterns among poultry farmers in Kiambu County and characterized phenotypic resistance in Escherichia coli and Enterococcus spp. isolated from humans, chickens, and chicken environments.

Materials and methods: A cross-sectional study was conducted from June to September 2024, involving 102 poultry farms. Farm demographics and AMU data were collected using a semi-structured questionnaire. Archived E. coli (n = 92) and Enterococcus spp. (n = 101) isolates from chicken handlers' hands, chickens, and environmental samples were subjected to antimicrobial susceptibility testing using the Kirby-Bauer method per Clinical and Laboratory Standards Institute (CLSI) 2024 guidelines. Descriptive and inferential statistics, including logistic regression with false discovery rate correction, were used to assess associations between AMU and phenotypic resistance.

Results: Macrolides (69%), tetracyclines (48%), and sulfonamides (21%) were the most commonly used antimicrobials; 7% of farms reported colistin use. Among E. coli isolates, resistance was highest to ampicillin (77%), tetracycline (72%), and trimethoprim-sulfamethoxazole (49%), with 35% exhibiting multidrug resistance (MDR). No carbapenem resistance was detected. Enterococcus isolates showed high erythromycin resistance (61%) and moderate ciprofloxacin resistance (26%), with 6.9% exhibiting MDR; no vancomycin-resistant enterococci (VRE) were observed. Penicillin use strongly predicted ampicillin resistance in both organisms, whereas sulfonamide use was associated with reduced trimethoprim-sulfamethoxazole resistance. Macrolide use did not correlate with erythromycin resistance.

Conclusion: High AMU in poultry farming, particularly of macrolides, tetracyclines, and sulfonamides, has created significant selection pressure, contributing to MDR emergence across One Health interfaces. Detection of resistance in humans, poultry, and shared environments underscores the bidirectional risk of AMR transmission. Strengthened antimicrobial stewardship, regulation of critically important antimicrobials, and enhanced farm hygiene are essential to mitigate AMR. These findings directly support Kenya's Vision 2030 and SDGs targeting health, responsible production, and environmental protection.

Background and aim: Free-grazing duck (FGD) production systems play a vital economic role in Thailand but are also recognized as potential sources and amplifiers of avian influenza (AI) viruses at the human-animal-environment interface. Understanding the knowledge, attitudes, and practices (KAP) of individuals involved in FGD production is crucial for effective prevention and control of AI. This study aimed to assess AI-related KAP levels among FGD farmers and related workers in central Thailand and to identify demographic, occupational, and behavioral factors linked to these KAP outcomes.

Materials and methods: An analytical cross-sectional survey was conducted from January to May 2023, involving 101 participants working in FGD production systems across Ayutthaya, Suphan Buri, and Nakhon Sawan provinces. Data were obtained through face-to-face interviews using a structured, expert-validated questionnaire that covered socio-demographic details, animal exposure, vaccination history, and AI-related knowledge, attitudes, and practices. KAP scores were determined using standardized scoring criteria. The relationships between KAP scores and explanatory variables were analyzed using simple and multiple linear regression.

Results: The average knowledge score was 8.65 ± 2.39 (out of 12), the average attitude score was 3.63 ± 0.36 (out of 5), and the average practice score was 3.17 ± 0.38 (out of 5). Overall, 58.4% of participants demonstrated good knowledge, 66.3% exhibited positive attitudes, and 38.6% reported good preventive practices against AI. Knowledge scores were significantly linked to daily working hours with FGDs, contact with other animals, and influenza vaccination history. Positive attitudes were significantly influenced by educational level and occupation, while good practices were associated with higher education, type of FGD production system, animal contact, and vaccination during poultry work. Moderate positive correlations were observed between knowledge and attitude scores and between attitude and practice scores.

Conclusion: This study offers the first comprehensive assessment of KAP regarding AI among FGD farmers in Thailand. Although knowledge and attitudes about AI were generally adequate, preventive measures were relatively inadequate. Improving targeted public health education, increasing vaccination awareness, and implementing One Health-based biosecurity measures are recommended to boost AI prevention and readiness in FGD production systems.

Background and aim: Canine gingival masses are common oral lesions with variable biological behavior, ranging from reactive hyperplasia to malignant neoplasia. Although routine cytology is widely used for initial evaluation, diagnostic overlap between benign and malignant lesions may limit accuracy when relying solely on morphology. This study aimed to develop and validate a trimodal cytological framework that integrates cytomorphometric analysis, argyrophilic nucleolar organizer region (AgNOR) staining, and micronuclei assay to enhance cytological differentiation and objectively characterize proliferative and genotoxic alterations in canine gingival masses.

Materials and methods: Cytological specimens were obtained through fine-needle aspiration from gingival masses of 46 dogs and classified as epithelial hyperplasia (n = 11), benign neoplasms (n = 14), and malignant neoplasms (n = 21), with histopathology serving as the reference standard. Cytomorphometric parameters (nuclear diameter, nuclear area, cytoplasmic area, cellular diameter (CD), and nuclear-to-cytoplasmic [N:C] ratio) were measured using digital image-analysis. Cellular proliferation was evaluated by AgNOR silver staining, while genomic instability was assessed with acridine orange-based micronuclei assay. Group comparisons were conducted using one-way analysis of variance, and relationships among parameters were examined using Pearson's correlation coefficient.

Results: Significant differences were observed among lesion categories for AgNOR count, micronuclei frequency, and most cytomorphometric parameters (p < 0.01), except for CD. Malignant neoplasms showed the highest AgNOR count (4.04 ± 2.81) and micronuclei frequency (7.76 ± 2.10), indicating increased proliferative activity and genotoxic damage. Epithelial hyperplasia presented larger nuclear and cytoplasmic dimensions, while the N:C ratio was highest in benign neoplasms (0.44 ± 0.23). The N:C ratio showed significant correlations with AgNOR (r = 0.319, p = 0.030) and micronuclei counts (r = 0.317, p = 0.032). A strong positive correlation was found between AgNOR and micronuclei counts (r = 0.631, p < 0.01).

Conclusion: The integration of cytomorphometry, AgNOR staining, and the micronuclei assay creates a strong, quantitative cytological framework that improves diagnostic accuracy for canine gingival masses. This three-part approach decreases subjective interpretation, enhances detection of malignant changes, and can easily be adapted to digital and AI-supported cytopathology systems in veterinary clinical practice.

Background and aim: Essential oils (EOs) are promising natural modifiers of rumen fermentation and methane production; however, their volatility and rapid degradation limit their effectiveness. Microencapsulation can shield bioactive compounds and allow controlled release. Insect-derived proteins, especially from black soldier fly (BSF; Hermetia illucens L.), offer a sustainable and functional wall material, yet their use for rumen-targeted delivery remains unexplored. This study aimed to assess the effects of microencapsulated-lemongrass oil (M-LEO) using BSF protein as a biopolymer wall on gas kinetics, nutrient degradability, rumen fermentation parameters, microbial populations, and methane output in vitro.

Materials and methods: A completely randomized design was used with five dietary treatments containing M-LEO at 0, 2, 4, 6, and 8% of total dry matter (DM) substrate. In vitro rumen fermentation was performed using rumen fluid from Holstein-crossbred dairy cattle. Fermentation was measured at 12, 24, and 48 h for gas kinetics, in vitro dry matter degradability (IVDMD) and in vitro organic matter degradability (IVOMD), pH, ammonia-nitrogen (NH₃-N), volatile fatty acids (VFAs), methane production, and microbial populations quantified by real-time polymerase chain reaction.

Results: M-LEO showed high encapsulation efficiency (85.2%) and significant bioactive content. Supplementing with M-LEO notably improved gas production kinetics and nutrient degradability, with optimal effects at 6% of total DM. At this level, IVDMD and IVOMD increased by up to 11.5% and 10.5%, respectively. Total VFA and propionate concentrations rose significantly (p < 0.05), while acetate proportion and the acetate-to-propionate ratio decreased. Rumen pH and NH₃-N levels stayed within optimal ranges and were unaffected by treatment. Methane production was substantially reduced, with decreases of up to 48.8% at 48 h compared to the control. Additionally, M-LEO boosted populations of key cellulolytic bacteria (Fibrobacter succinogenes, Ruminococcus albus, and Ruminococcus flavefaciens) and Megasphaera elsdenii, while significantly suppressing methanogenic archaea (Methanobacteriales).

Conclusion: Microencapsulation of lemongrass oil with BSF protein effectively enhances rumen fermentation efficiency and significantly decreases methane emissions in vitro. This innovative insect-protein delivery system provides a sustainable and climate-friendly feed additive approach, deserving further validation in vivo.

Background and aim: Transportation is an unavoidable management practice in cattle production and is a major source of physiological, endocrine, and oxidative stress, leading to impaired welfare, immunity, and productivity. Drug-free and food-safety-compatible interventions to alleviate transport stress remain limited. Acupuncture has shown stress-reducing effects in livestock; however, conventional metal needles are incompatible with Hazard Analysis and Critical Control Point (HACCP) systems. Recently developed biodegradable starch-based Circular transdermal needles (CTNs) offer a novel HACCP-compliant alternative. This study aimed to evaluate the effects of ear acupuncture using starch-based CTNs on transport-induced stress responses and oxidative status in calves.

Materials and methods: Five clinically healthy male Holstein calves (3-4 months old) were subjected to a crossover experimental design involving a short-distance transport challenge (2 h 20 min). Calves received either ear acupuncture at the Jisen acupoints using starch-based CTNs or no treatment (control), with a washout period between treatments. Heart rate and rectal temperature were recorded, and blood samples were collected prior to transport (PRE), immediately after transport (POST1), and 2 days after transport (POST2). Serum stress markers (cortisol, catecholamines, oxytocin), oxidative stress indices (derivatives of reactive oxygen metabolites [d-ROMs], biological antioxidant potential [BAP], and BAP/d-ROMs ratio), and biochemical parameters were analyzed. Data were expressed as relative changes between time points and statistically evaluated at p < 0.05.

Results: Acupuncture treatment suppressed post-transport increases in heart rate and rectal temperature compared with controls. Cortisol responses were attenuated in the acupuncture group, while oxytocin levels were consistently higher, indicating enhanced stress tolerance. Importantly, the BAP/d-ROMs ratio was significantly higher in acupuncture-treated calves at POST1 and POST2, reflecting improved oxidative balance and reduced oxidative stress. Although serum amyloid A increased slightly after acupuncture, no local inflammation or adverse reactions were observed at needle insertion sites.

Conclusion: Ear acupuncture using biodegradable starch-based CTNs effectively mitigated physiological, endocrine, and oxidative stress responses associated with short-distance transport in calves. This HACCP-compatible, drug-free approach represents a novel and practical strategy to enhance animal welfare and stress resilience in cattle production systems.

Background and aim: Avian infectious bronchitis virus (IBV) is a highly contagious coronavirus that causes severe respiratory, renal, and reproductive disease in chickens, resulting in significant economic losses in the poultry industry worldwide. The high mutation and recombination rates of IBV, especially in structural proteins like the spike glycoprotein, limit the effectiveness of current live attenuated and inactivated vaccines. This study aimed to design and computationally evaluate a novel multi-epitope vaccine (MEV) targeting the highly conserved RNA-dependent RNA polymerase (RdRp) of IBV in order to provide broad and lasting immune protection.

Materials and methods: The RdRp protein (NCBI: NP_740629.1) was chosen as the vaccine target due to its high sequence conservation and crucial role in viral replication. B-cell lymphocyte, cytotoxic T-lymphocyte, and helper T-lymphocyte epitopes were predicted using various immunoinformatics tools, followed by strict screening for antigenicity, non-allergenicity, non-toxicity, interferon-γ induction potential, and lack of homology with Gallus gallus proteins. The selected epitopes were assembled into a single construct with suitable linkers, incorporating avian β-defensin 8 as an N-terminal adjuvant. The vaccine candidate was analyzed in silico for physicochemical properties, structural stability, solubility, molecular docking with chicken Toll-like receptor 7 (TLR7), molecular dynamics, and immune response simulation.

Results: The final multi-epitope construct showed favorable physicochemical properties, including high stability (instability index: 25.74), hydrophilicity, and predicted solubility (Protein-Sol score: 0.504). Structural modeling and validation confirmed a reliable tertiary structure. Molecular docking demonstrated strong, stable binding to TLR7, supported by multiple hydrogen bonds and salt bridges, while molecular dynamics analysis indicated sufficient flexibility for immune recognition. Immune simulations forecasted robust humoral and cellular immune responses, characterized by increased IgG levels, expansion of memory B and T cells, and a Th1-biased cytokine profile with significant interferon-γ production.

Conclusion: This immunoinformatics-designed RdRp-based MEV is a promising candidate for broad-spectrum protection against IBV. By targeting a conserved non-structural protein, it may address limitations linked to strain-specific vaccines. In vitro and in vivo testing is needed to confirm its safety, immunogenicity, and protective efficacy in poultry.

Background and aim: Swine housing and management systems strongly influence respiratory health through their effects on air quality, ventilation, and environmental exposure. However, quantitative, lobe-specific evidence describing how different management systems affect pulmonary microarchitecture remains limited. This study aimed to compare alveolar structure, fibrosis, collagen deposition, and alveolar macrophage distribution in swine raised under hygienic, beta-agonist-free rearing, and free-range systems.

Materials and methods: Fifteen clinically healthy male crossbred (Large White × Landrace) swine were allocated to three management systems (n = 5 per group): hygienic, beta-agonist-free rearing, and free-range. Lung samples were collected from the right cranial, middle, and caudal lobes following humane slaughter. Sections were stained with Masson's trichrome for collagen visualization. Quantitative histomorphometric analyses included alveolar wall thickness, alveolar space area, fibrosis distribution (%), semi-quantitative fibrosis score, collagen intensity (mean gray value) in bronchial hyaline cartilage, and alveolar macrophage density (AMD). Image analysis was performed using ImageJ, and observers were blinded to group allocation. Data were analyzed using one-way analysis of variance with Tukey's post hoc test (p < 0.05).

Results: Marked lobe-specific differences were observed among management systems. Swine raised under beta-agonist-free rearing exhibited significantly thicker alveolar walls, reduced alveolar space area, higher fibrosis distribution and scores, increased collagen accumulation, and elevated AMD, particularly in the middle and caudal lobes. In contrast, free-range swine demonstrated thinner alveolar septa, wider alveolar spaces, lower fibrosis indices, and reduced macrophage infiltration, indicating preserved pulmonary architecture and reduced inflammatory remodeling. The hygienic group consistently showed intermediate values across most parameters, reflecting balanced structural adaptation under controlled housing conditions.

Conclusion: Swine management systems are associated with distinct patterns of pulmonary structural and immunological adaptation. Beta-agonist-free rearing was linked to early fibrotic remodeling and increased immune activation, whereas free-range management supported structural preservation and lower inflammatory burden. This study provides the first quantitative, lobe-specific histomorphometric comparison of pulmonary remodeling across different swine management systems, offering valuable insights for welfare-oriented and sustainable livestock production strategies.

Background and aim: Elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV-HD) is a leading cause of fatal hemorrhagic illness in juvenile Asian elephants (Elephas maximus), often requiring urgent plasma transfusion. However, the biochemical stability of fresh-frozen plasma (FFP) during long-term storage has not been systematically evaluated in this species. This study assessed the stability of key plasma proteins, fibrinogen, clotting factor VIII, immunoglobulin G (IgG), and albumin, in FFP stored at -20°C for 4, 8, and 12 months, and compared them with fresh plasma to determine suitability for emergency clinical use.

Materials and methods: Plasma samples were collected from 20 healthy elephants and processed into fresh and frozen aliquots. Fibrinogen concentrations were quantified using the Clauss assay, factor VIII activity via a one-stage clotting assay, and IgG and albumin concentrations using colorimetric methods. A repeated-measures generalized linear model evaluated the effects of storage duration on protein stability, with post hoc Tukey adjustments.

Results: Fibrinogen concentrations remained stable during storage, with no significant differences at 8 or 12 months compared with fresh plasma. Factor VIII activity declined progressively, with a significant 16% reduction after 12 months (p < 0.001), though values remained within clinically acceptable ranges. Conversely, IgG and albumin concentrations increased significantly during frozen storage, with 37% and 21% higher values, respectively, at 12 months, likely reflecting cryoconcentration. Neither sex nor other covariates significantly influenced protein stability.

Conclusion: This study provides the first evidence that elephant FFP stored at -20°C retains acceptable biochemical stability for up to 12 months. Although factor VIII activity decreases over time, fibrinogen remains stable, and immunoproteins increase, supporting the clinical utility of stored plasma in EEHV-HD emergencies. These findings provide foundational guidance for establishing elephant plasma banking protocols, improving readiness for rapid intervention, and advancing One Health-aligned conservation strategies for endangered megafauna.